Asbestos fluffing



June 18, 1946. Q PHARQ 2,402,203

ASBESTOS FLUFFING- Original Filed Nov. 21, 1942 INVENTOR 2o 15' 40 v M XITToRNEY Patented June 18, 19th snnsros rwrrmo Lee C. Pharo, Theti'ord Mines, Quebec, Canada, assignor to Johnsons Company, Thetford Mines, West, Quebec, Canada Original application November 21, 1942, Serial No.

466,522, now Patent No. 2,386,713, dated Octoher 9, 1945. Divided and this application February 17, 1944, Serial No. 522,811. In Canada October 14, 1942 2 Claims. 1

. Introduction This invention relates to the flufilng of asbestos and the application is a division of application Serial No. 466,522, filed Nov. 21, 1942.

It is an object of the invention to provide a method and apparatus for freeing individual asbestos fibers from masses. his a further object of the invention to provide a method and-apparatus of this nature capable of liberating asbestos fiber for textile use;

Detailed description In carrying out the inventionthe flberized asbestos is blown against a resistance element, so as to liberate the fibers without injury. The invention will be understood more speclfically by reference to a description of a preferred form of apparatus in which it is embodied, in conjunctionwith the accompanying drawing in which:

Figure 1 is a side elevation partly in section showing this preferred form of apparatus.

Figure 2 is a plan view of the apparatus shown in Figure 1.

Figure 3 is a fragmentary cross-section along the line 3-3 of Figure 1 illustrating the manner of attachment of the resistance element or screen.

Referring more particularly to the drawing, the device consists of a spiral tubular casing ill made preferably of suitable sheet material. This casing includes a floor It, a ceiling l2 and side walls l5. In the particular embodiment shown, the casing ill is provided with an entrance l6 and a discharge opening I1. Intermediate these openings the casing is looped in an abrupt spiral. The floor ii is surfaced with a coarse mesh wire screen it presenting a ribbed surface. This screen is held in place by brackets 22 secured to the floor it by nuts and bolts 25. The ceiling i2 is similarly provided with ribbing in the'form of ascreen held in place by a bracket 32, and mitts bolts Adjacent the entrance it is a pair of air suppipes controlled by a valve (not shown). These pipes are connected with a suitable source of air supply capable of giving an air pressure.

the outlet of the pipes of about 100 lbs. per square inch. In this particular apparatus the is of internal diameter of about inch. mic the is provided with openings s provided with sliding doors i fitin suitable guideways t5.

C32 utton n om masses of asbestos which has been artialhr fiberized as for instance accordt..-e method described in United States o. 2,219,277, October 22, 1940. It may access to the inside of the casing. These also been subjected to other special-treatment. as for instance that described in co-pending application Serial No. 466,522, filed Nov. 21, 1942. and for other purposes.

A-method of treatment employing the apparatus described is as follows. The compressed air is turned on by the control valve setting up a high pressure blast at the entrance i6 and which is diverted through the abrupt spiral passage presented by the casing Ill. The asbestos masses which have been at least partially fiberized are fed in a suitable manner and are immediately taken up by the air stream and forced through the helical casing at high speed. In their passage through the casing they impinge on the resistance elements or screens 20 and 3t and are thus subjected to a disintegrating action. The resistance of the screens is, however, only partial and the air-borne masses are free to leave the screens and to move further through the passage formed in the casing. Hence break- -age of individual fibers is minimized.

The nature of the fiufling method accomplished by this apparatus is important. Too much emphasis cannot be laid on the fact that asbestos must be handled carefully so as to liberate the fibers without breaking them. The fluifing or teasing action of the applicants process also departs from any beating action on the fiber masses. They are blown under relatively heavy air pressure against the undulating or ribbed surface presented by the coarse screen lining of the fluffer tube. At all times, the fibers are free to leave the screen against which they have struck with a glancing blow as the air pressure carries them forward. At no time is any chopping action at right angles to the fiber as experienced in a Jumbo or grader employed. The action is comparable to "grabbing? and releasing or "pluclring at the masses, which is highly effective in liberating the individual fibers.

It should also he explained that air is forced into the mass of fiber before the air has fully expanded. Therefore, the further expansion of the air which has been forced; into the asbestos mass tends to pull the fibers apart, that is, a minor explosion takes place from within the fiber mass. until the compressed air has reached atmospheric pressure.

It will be understood that, without departing fromthe spirit oi the invention or the scope of the claims, various modifications may be made 3 in the speciilc'expedients described. The latter are illustrative only and not offered in a restricting sense, it being desired that only such limitations shall be placed thereon as may be required by the stateof the prior art.

The sub-titles used throughout the specification are merely to simplify reference thereto and should otherwise be disregarded.

I claim:

1. An apparatus for liberating fibers of fibrous material from masses thereof comprising a continuous substantially helical unobstructed substantially air tight wind tunnel, a screen lining at least one continuous surface or the inner wall of said wind tunnel and constituting a. roughened area, said wind tunnel h the screen disposed along the inner wall surface thereof whereby only a single passage is provided in said tunnel,

means for concentrating a blast of high pressure air in said tunnel adjacent an entrance end thereof, an entrance to said age whereby said fibrous material may be fed directly into said 4 blast, and a discharge opening at the opposite end of said wind tunnel for discharging liberated fibers therefrom.

2. An apparatus for liberating fibers oi fibrous materials from masses thereof, comprisim, n continuous substantially helical unobstructed substantially airtight wind tunnel, ribbing extending from at least one continuous surface of the inner wall of said wind tunnel and constituting a roughened area, said wind tunnel having the ribbing disposed along the inner wall surface thereoi'whereby only a single passage is provided in said tunnei which is lined by said ribhing, means for concentrating a blast of high pressure air in tunnel adjacent-an entrance end thereof, an entrance to said passage whereby said fibrous material may be fed into said blast, and a discharge one at the opposite end of said wind tunnel for discharging liberated fibers therefrom. 

